Raising rear axle - to shorten turning radius

[wbdodgeiv]

I cannot make the turn into my driveway without heming and hawing, and once in the driveway it is a steep uphill turn. The scrubbing tandems are chewing up my asphalt. First thought was to unlock one side of the front tandem axle to eliminate the chewing, but this will get me stuck in the yard if I run off the driveway (it happens...)

There is a lot of articulation in the bogey axle setup, what do you think would happen if some sort of device such as airbags or a winch was to lift the rear axle or push down on the front to raise the rear axle? It seems to me this would take 2ft off the wheelbase and eliminate the scrubbing. If I got stuck a switch flip in the cab could drop the rear axle down and it is a 6x6 again.

I know there was a large thread on driving with a chained up axle, but I am talking about something that is able to be done on the fly, at low speeds, for the purpose of low speed no load maneuvering. Am considering an experiment in a parking lot to measure turning radius then chain up the rear axle and measure again.

 

[466Navastar]

"push" hydraulic cylinders for front axle or "pull" hydraulic cylinders on rear axle would likely work - looks like tailgate will be WAY up in the air when you actuate though

 

[466Navastar]

but you would need a "float" feature in the cylinder controls to allow normal articulation while operating normally....not sure how long these cylinders would last

 

[wbdodgeiv]

I was thinking that replacing the front bump stop with an airbag would be the easist. A 9k import winch is ~$350, this could lift the rear axle as well. I could let the winch go slack to allow for normal movement. A limit switch on the cable could limit spoolout when lowering the axle. I have a cross member directly over the pumpkin that could be used to either attach the winch or a pulley.

It would look goofy, but the 3-4pt turns suck. I didn't know about the whole lockout problem between 1st and reverse and got the truck stuck blocking the entire roadway for the 30min it took to raise and crib both rear axles to release the driveline bind that was locking the transmission. Fortunately I didn't break anything, to avoid that again is easily worth $400.

 

[59apache]

whats about this:
using a pullcylinder and wire rope sling to lift the axle. if you not use it, the axle moves free in the sling.

 

[dc3coyote]

I would imagine that you could put a airbag on the front axel, and a limiting strap on the rear, but why not just reinforce your driveway to handle the added stress. Putting those kind of mods on your truck is going to hamper your reliability, as well as cost you in the offroad department. I just put gravel down next to my yard for the turns when it gets too rutted just rake it out.

 

[Boss Doug]

 

[patracy]

I would say running large enough airbags should work for your idea. Just have to make sure they have plenty of length to them. You'd want a valve would allow them to vent to atmosphere so they wouldn't hamper (as much) the suspension when not in use.

 

[oldMan99]

suscribed

 

[Bob H]

I have seen the installation of a lock out hub on the back axle.
The owners tells me it made a world of difference in the ease of turning.
Most of the scrubbing is due to both axles being tied together.
You can remove the rear drive shaft to test this out before spending money.

 

[oldMan99]

I have seen the installation of a lock out hub on the back axle.
The owners tells me it made a world of difference in the ease of turning.
Most of the scrubbing is due to both axles being tied together.
You can remove the rear drive shaft to test this out before spending money.

To facilitate the flat towing (all 4 wheels on the ground) of regular rear wheel drive automatic transmission vehicles there is a company that makes a drive shaft disconnect device. You install it on the driveshaft and drive as normal, when you want to flat tow (and not tear up the automatic transmission) you pull a lever that is attached to a cable that unlocks or disconnects the driveshaft. When your done push the lever back and your connected.

I wonder if maybe they make one that could be installed on the inter-axle driveshaft of a Deuce so that you could do this on the fly without having to get out of the truck.

If not, maybe one could be home-brewed using the same design they use only beefing it up.?

This assumes of course that the above mentioned shaft removal test proves successful.

 

[mktopside]

To facilitate the flat towing (all 4 wheels on the ground) of regular rear wheel drive automatic transmission vehicles there is a company that makes a drive shaft disconnect device. You install it on the driveshaft and drive as normal, when you want to flat tow (and not tear up the automatic transmission) you pull a lever that is attached to a cable that unlocks or disconnects the driveshaft. When your done push the lever back and your connected.

I wonder if maybe they make one that could be installed on the inter-axle driveshaft of a Deuce so that you could do this on the fly without having to get out of the truck.

If not, maybe one could be home-brewed using the same design they use only beefing it up.?

This assumes of course that the above mentioned shaft removal test proves successful.

Remco's Drive Shaft Coupling | Remco Towing

 

[kwiksilver]

Its already an open diff I don't know how unlocking hubs would help.

 

[patracy]

Its already an open diff I don't know how unlocking hubs would help.

Putting one locking up on one of the tandem axles will help. There is no differential between the tandem axles so the front axle pinion speed must remain the same as the rear axle pinion speed. All four wheel assemblys travel in slightly different arcs causing speed differences.

 

[motomacguyver]

It would look goofy, but the 3-4pt turns suck. I didn't know about the whole lockout problem between 1st and reverse and got the truck stuck blocking the entire roadway for the 30min it took to raise and crib both rear axles to release the driveline bind that was locking the transmission. Fortunately I didn't break anything, to avoid that again is easily worth $400.

This might be a dumb question, but what is "the lockout problem between 1st and reverse?"

 

[mudguppy]

whats about this:
using a pullcylinder and wire rope sling to lift the axle. if you not use it, the axle moves free in the sling.

i believe this would be the best option. this is similar to the concept i suggested in a similar thread about a 5T.

i would install two hydraulic cylinders horizontally in the frame rails. install a crossmember in the frame above the rear axle that incorporates a cross-shaft with rollers. the cylinders would pull cables across the rollers, lifting the rear axle. for normal drive, extend the cylinders fully, creating slack in the cables, to allow for regular axle articulation.

a simple electric/hydraulic unit could be used to operate this via toggle-switch in the cab.


getting airbags with long enough travel would be cumbersome; it will take a large amount of air to fill the bags with enough pressure to lift the rear. it will likely drain the onboard tanks and still require quite a bit of fill time to take a long-travel bag from completely empty to completely full. so you'll have to wait to finish filling the bags as well as re-filling the tanks.

 

[tco3129]

I have the same scenerio with my driveway. In my case I can go past my drive to a large turnaround spot and return from a different angle. Tho I live only 1 1/2 mi. from work. I drive 5 1/2 mi. Any time in my deuce is GOOD time. Any mods to add convience and take away from the original are not for me but maybe for others. In your situation I'd BOB it.

 

[tco3129]

BTY I did think the driveshaft disconnect rig was interesting.

 

[s1036s]

thoughts

just thinking out loud. But if you raised the front rear axle, would there be any driveline angle issues? I would think it would be easier to raise the rear axle, but how far would you have to go before the tire would come off the ground. Would it be bottoming out on bump stops, or the bed of the truck.
If you lifted one axle or the other, the wheels will continue rotating...
The easiest would be a winch like previously stated.

 

[mudguppy]

... But if you raised the front rear axle, would there be any driveline angle issues? ...

not unless you raised the axle higher than the OE suspension travel allows. but that isn't the issue; raising the intermediate axle would create a longer wheelbase and make for an even larger turning radius - the exact opposite of what the OP intends to accomplish.

... how far would you have to go before the tire would come off the ground. ...

probably about that far, yes.